What is AC voltage controller? | Advantages, Disadvantages and Application Of AC voltage controller
AC Voltage Controller :
AC voltage controllers are thyristor based devices which converter fixed alternating voltage into variable alternating voltage directly without change in frequency.
To obtain the desired performance of Electrical system ac voltage controlled.
Block diagram of ac voltage controller is shown in below image 👇
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| Block Diagram of AC voltage controller |
If a thyristor switch is connected between ac supply and load, the power flows controlled by varying r.m.s value of ac voltage applied to the load.
The ac voltage level can also be changed by tap-changing transformers, magnetic amplifiers, etc.
Now, thyristor and Trial ac regulators have replaced them in most of the applications because of compact size, fast control, high efficiency etc.
However, ac regulators using thyristors and TRIAC introduce objectionable harmonics in the circuit.
Advantages
1. These having high efficiency.
2. Losses are less
3. Simple in circuit configuration.
4. It requires less maintenance.
5. These are compact in size
Disadvantages
1. The load current is not pure sinusoidal in phase control.
2 Harmonics are present in load current.
3. The value of voltage is sharply changed due to phase angle control.
Applications of AC voltage controllers
1. Speed control of poly phase AC motors.
2. ON load transformer tap changing
3. For industrial heating.
4. For starting of induction motor.
5. Fan control
6. Electrical welding.
Types of AC voltage converters:
The ac voltage controllers can be single phase or three phase And it can be unidirectional or bidirectional. So, the types of AC Voltage converters are,
Single Phase ac voltage controller :
(1) Single Phase Unidirectional (half wave controller)
(2) Single Phase Bidirectional (Full wave controller)
Three Phase ac voltage controllers :
(1) Three Phase Unidirectional (half wave controller)
(2) Three Phase Bidirectional (Full wave controller)
